The present invention relates to a surge arrester assembly comprising a plurality of parallel-connected surge arrester units, each comprising a stack of a plurality of cylindrical arrester elements, preferably made of metal oxide varistor material, for example ZnO blocks, which are arranged one after the other in the axial direction of the arrester elements between two end electrodes and are surrounded by an elongated outer casing of polymeric material.
In connection with applications which require parallel connection of a great number of ZnO blocks, as, for example, for protection of series capacitors or the neutral bar in a high voltage direct current (HVDC) station, the enclosure constitutes a significant part of the arrester cost since both mechanical and electrical demands are placed thereon.